"""
HTTP Connection Pool Manager.
Optimized for 150 concurrent users with frontend-offloaded architecture.
"""

import requests
from requests.adapters import HTTPAdapter
from urllib3.util.retry import Retry
from config import (
    GPT_POOL_SIZE, TTS_POOL_SIZE, MISTRAL_POOL_SIZE,
    TRANSCRIPT_POOL_SIZE, CLOUDINARY_POOL_SIZE, BOARD_PROCESSOR_POOL_SIZE,
    ICONS8_POOL_SIZE, TELEGRAM_API_POOL_SIZE, CARDS_API_POOL_SIZE
)


def _create_session(pool_size, pool_block=True, retries=2):
    """Create a requests.Session with connection pooling."""
    session = requests.Session()

    retry_strategy = Retry(
        total=retries,
        backoff_factor=0.5,
        status_forcelist=[502, 503, 504],
        allowed_methods=["POST", "GET", "PUT"],
    )

    adapter = HTTPAdapter(
        pool_connections=pool_size,
        pool_maxsize=pool_size,
        pool_block=pool_block,
        max_retries=retry_strategy,
    )

    session.mount("https://", adapter)
    session.mount("http://", adapter)

    return session


# PRIMARY pools
gpt_session = _create_session(GPT_POOL_SIZE)
board_processor_session = _create_session(BOARD_PROCESSOR_POOL_SIZE)
mistral_session = _create_session(MISTRAL_POOL_SIZE)
transcript_session = _create_session(TRANSCRIPT_POOL_SIZE)
cloudinary_session = _create_session(CLOUDINARY_POOL_SIZE)
telegram_api_session = _create_session(TELEGRAM_API_POOL_SIZE)

# FALLBACK-ONLY pools
tts_session = _create_session(TTS_POOL_SIZE)
icons8_session = _create_session(ICONS8_POOL_SIZE)

# Cards Microservice pool
cards_service_session = _create_session(CARDS_API_POOL_SIZE)

print("HTTP Connection Pools initialized:")
print("   GPT:              {} connections".format(GPT_POOL_SIZE))
print("   Board Processor:  {} connections".format(BOARD_PROCESSOR_POOL_SIZE))
print("   Mistral:          {} connections".format(MISTRAL_POOL_SIZE))
print("   Transcript:       {} connections".format(TRANSCRIPT_POOL_SIZE))
print("   Cloudinary:       {} connections".format(CLOUDINARY_POOL_SIZE))
print("   Telegram API:     {} connections".format(TELEGRAM_API_POOL_SIZE))
print("   TTS:              {} connections (fallback)".format(TTS_POOL_SIZE))
print("   Icons8:           {} connections (config only)".format(ICONS8_POOL_SIZE))
print("   Cards Service:    {} connections (microservice)".format(CARDS_API_POOL_SIZE))